Brain & Spinal Tumors

Neuronavigation Tumors of the brain and spine may be primary (arising from the brain and spinal tissues) or secondary / metastatic (having spread from other parts of the body such as lung, breast etc). Primary tumors may be benign, malignant or sometimes indeterminate. The common primary tumors of the brain include glioma, meningioma, and pituitary adenoma. Other types of brain tumors include: acoustic neuroma, brain stem glioma, craniopharyngioma, medulloblastoma, ganglioglioma, chordoma, schwannoma, germ cell tumors, and pineal gland tumors. A detailed description of these tumors can be found at the American Cancer Society web page . The Brain Tumor Society web page also has useful information about brain tumor facts and statistics.

Unlike other malignant tumors in the body, tumors of the brain and spine rarely spread to other organs. However, the location of these tumors can interfere with the crucial life functions of the brain and spinal cord.

Signs & Symptoms

General symptoms for brain and spinal cord tumors include headaches, nausea or vomiting, weakness or numbness in arms or legs, trouble walking or uncoordinated walking, seizures or convulsions, changes in vision or unusual eye movements, drowsiness, changes in memory, and changes in speech. There are also particular symptoms associated with specific locations of brain tumors. Tumors of the cerebellum — which is located at the back of the brain and controls movement — cause poor coordination when walking, difficulty performing fine motor movements of the arms and legs, and changes in speech. Symptoms of a tumor of the cerebral right or left hemisphere affect the opposite side of the body corresponding to the tumor. Tumors of the spinal cord affect both sides of the body: arms and legs in case of the cervical spinal cord, and both lower extremities if the tumor is located in the thoracic spine.

Diagnosis

Brain tumors are usually diagnosed or suspected after a CT scan is performed when a patient presents with the above mentioned symptoms. A MRI scan of the brain with and without contrast (gadolinium) is performed as the next step as this offers a more detailed image of all brain structures as well as the surrounding edema or swelling of the brain and the shift or displacing effect caused by the tumor. Further a MRI is more sensitive to subtle changes in the brain tissue and may detect smaller tumors or strokes not detected by a CT scan.

The other imaging / diagnostic methods that are employed include:

MRI spectroscopy (MRS) - MR spectroscopy analyzes the chemical composition of the tumor mass providing clues to the differentiation of infection, demyelination (as in multiple sclerosis or MS), stroke and malignancy.

Cerebral Angiography & Embolization

This is performed by inserting a small catheter into the femoral artery in the groin and threading it to the carotid and vertebral arteries in the neck. Contrast dye is then injected while the circulation in the brain is studied using digital X ray technology. This is useful in delineating the normal and abnormal blood vessels of the brain and the tumor. In specific situations the same technique is used to obliterate tumor blood vessels ( pre-operative embolization) prior to surgery.

Functional MRI (fMRI)

When tumors are located close to critical functional brain, fMRI is used to locate the functional areas by asking the patient to perform tasks such as movement and speech as the MRI scan is done. This provides additional information to the surgeon for planning and execution of surgical excision of tumors located in such eloquent areas of the brain.

Positron Emission Tomography (PET)

Identifies areas of increased metabolic activity. This is commonly used in staging of other cancers of the body such as lung, breast etc. In the brain it is useful in differentiating recurrent tumor from radiation induced necrosis (cell death) as these two conditions cannot be readily distinguished based on routine MRI scans.

CT Scan of Chest/Abdomen/Pelvis

These scans are done to look for other tumors in the chest / abdomen / pelvis as a staging procedure. This helps in separating primary from secondary (or metastatic) tumors of the brain.

For a more detailed discussion of these diagnostic techniques visit the Radiological Society of North America’s Radiology Info website.

Definitive Diagnosis

A definitive diagnosis can only be established by performing a biopsy. A small piece of the tumor is removed and analyzed by the pathologist to establish the type of cells that make up the tumor and their grade or degree of malignancy.

Diagnostic vs. Excisional Biopsy

Based on the site, size and appearance on the MRI scan, certain tumors are first biopsied before further treatment decisions can be made. Such diagnostic biopsies are most often performed using the frameless stereotactic system. Such a system allows for precise positioning of the site of entry, safe path to the target and options for multiple targets as needed. The computer software calculates the depth, angle of approach and also provides continuous target guidance as the biopsy probe is advanced through the brain tissue.
More often larger tumors are biopsied during open surgery and are also completely excised at the same time.

Treatment

Intraoperative Monitoring Complete surgical excision of both benign and malignant tumors remains the mainstay of treatment. Most tumor operations are planned using the preoperative neuronavigation software that provide intra-operative guidance for surgical approach, extent of excision and avoidance of critical structures. A variety of advanced techniques are employed depending upon the location and type of the tumor. This video illustrates the surgical steps in a standard craniotomy insert link to video demo

Radiation Therapy

Most primary malignant tumors of the brain are also treated by external beam radiation therapy (XRT) after the tumor has been surgically excised. It usually involves small doses of radiation delivered over several consecutive days. This is done to prevent recurrence from tumor cells beyond the borders of surgical excision. In the case of secondary or metastatic tumors whole brain radiation therapy (WBXRT) is recommended to prevent growth of new metastasis. Alternatively stereotactic radiosurgery (SRS) may be employed for small localized tumors that have not been removed surgically.

For details of radiotherapy techniques visit:

Radiosurgery

This is a method for delivering high dose radiation to small targets with in the brain in a focused and precise manner in one sitting. Radiosurgery is a non invasive, out-patient same day procedure. This is achieved by placing a stereotactic head frame on the patient under local anesthesia and sedation. CT and/or MRI scans are obtained with the frame in position and using advanced treatment planning software the targets as well as their radiation arcs are delineated. Radiosurgery can be performed using either Gamma rays from a radioactive Cobalt source (GammaKnife) or Photons generated by a Linear Accelerator – Xknife, BrainLab, Cyberknife etc.

A more detailed discussion can be found at www.radiologyinfo.org/en/info.cfm?pg=stereotactic

Chemotherapy

Till about 10 years ago chemotherapy was thought to be of very limited benefit in the treatment of brain tumors. Currently a variety of chemotherapeutic options are available in the treatment of brain tumors and the field as well as the number of agents under investigation is rapidly growing. Temozolomide (Temodar) is the first line, oral chemotherapeutic agent that has FDA approval in the treatment of glioblastoma multiforme and anaplastic astrocytoma. A number of other agents are in various phases of clinical trials with exciting and promising early results.

The American Cancer Society website and the NCI website provide an overview about chemotherapy in general. This site provides an overview of chemotherapy for brain tumors www.braintumorfoundation.org/chemo.php . A more detailed discussion about individual agents can be found at www.chemocare.com/bio .

Clinical Trials

Several promising newer methods of treatment for malignant brain tumors are under investigation. While some are in very early Phase I stage many others have demonstrated early promising results and are in Phase II and Phase III trials.

Surgeons at NJBSC have initiated one such promising trial in the treatment of Glioblastoma Multiforme – the Celldex ACT III. - a phase II trial of the vaccine called CDX-110. ACT III investigates the safety and anticancer activity of adding CDX-110 vaccine to standard of care maintenance chemotherapy given after a patient with GBM has undergone surgery to remove the tumor, followed by radiation therapy and chemotherapy. NJBSC is one of several centers in the country and the only center in New Jersey offering this trial.

We will be participating in the Phase III trial evaluating Neuradiab as a treatment for primary glioblastoma multiforme, in a randomized two arm multi-center study targeting 380 patients in each arm comparing the current standard of care with a group receiving Neuradiab as an adjunct to the current standard of care. This multi institutional study is likely to be enrolling patients in early spring 2009. Neuradiab is a radioactive 131I-compound tagged to anti-tenascin monoclonal antibody. The dose is individualized based on the tumor size to deliver a 44-Gy resection cavity boost.

NJBSC is also developing a comprehensive neuro cognitive and health related quality of life study of all brain tumor patients before and after any form of treatment – surgery, radiotherapy, chemotherapy or radiosurgery – to assess outcomes from such interventions and their impact on the day-to-day well being of our patients.

For detailed information about clinical trials, what it means, what is involved and other frequently asked questions about clinical trials visit:

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